Electric switch



Mar. 6, 1923. 1,447,642. G. A. BURNHAM.

ELECTRIC SWITCH.

FILED SEPT.9, 1921. 2 SHEETSW'SHEEI I Z SHEETSSHEET Z.

G. A. BURNHAM. ELECTRIC SWITCH. FILED SEPLQ, 1921.

Mal. 6, 1923.

Patented Mar. 6, 1923.

UNITED s'rlvrr-:s

PATENT GFFICE.

GEORGE A. BURNHAI, 0F SAUGUS, MASSACHUSETTS, ASSIGNOR TO SEARS B.CONDIT, OF BROOKLINE, MASSACHUSETTS.

ELECTRIC SWITCH.

Application filed September 9, 1921. Serial No. 499,407.

To all 'whom it may concern:

Be `itknown that I, GEORGE A. BURNHAM, a citizen of the United States,residing at Sau us, in the county of Essex 'and State of assachusetts,have invented an Improvement in Electric Switches, of which thefollowing is a specification.

This invention relates to electric switches and has particular referenceto that type of switch adapted to be contained removably in an enclosingcell. A

A. cell adapted to contain. a switch with which this invention isconceived is usually provided with fixed connecting means for thecircuit leads and the connection between said fixed connecting means anda stationary switch member of the switch is usually a bar or strapremovably secured b bolts to both. When a switch is to be move fromv thecell, the bars must be unbolted; and the disconf necting operationrequires considerable time and may be ger as the fixed connecting meansmay be connected with a source of dangerously high potential.

Furthermore, the junction between the connecting bar and the fixed cellconnecting means and stationary switch members requires frequentcleaning to maintain a good electrical connection and reduce resistancelosses and heating, which may be considerable when the switch is adaptedto control circuits of considerable current capacity, as is usually thecase. With the usual bar form of connector, the circuit throu h the`switch usually must be interrupted be ore'the cleanking operation can beperformed, and it is highly desirable to maintain the continuity of thecircuit and not interrupt the circuit except through a necessaryoperation of the switch.

An object of this invention is to provide a switch with connecting meansarranged readily to disconnect the switch members from the cellconnecting means.

A. further object is to rovide connecting means, the contacting sur becleaned While maintaining the continuity of the circuit and whilecarrying current.

My invention maybe contained in a cell having ixed orstationarily-supported connecting means orhthe circuit leads and, aswitch adapted to be contained removably in said cell having exposedstationary switchmembers. Said cell connecting means and attended withlconsiderable danaces of which may switch members may be provided withterminal members having aligned openings therein and connecting rods maybe extended Ithrough said aligned openings ,and frictionally fitrotatably in said terminal members and connect sain cell connectingmeans and stationary switch members electrically. Saidv with A furtherobject `is generally to improve i the construction and .operation of anelectric switch.

Fig. 1 is a front elevation of a cell structure for a three-phaseswitching equipment with which my Vinvention is associated.

Fig. 2 is a sectional elevation along line 2 2 of Fig. 1.'

Fig. 3 is atop view of Fig. 2.

Fig. 4 is a detail, partly in section, of the terminal members .for acell connectin means and a stationary switch member an the conne'ctorextended between said terminal members.

Fig. 5 is a detail, in front sectional elevation, of a terminal memberfor a stationary switch member.

Fig. 6 is a detail of a wrench adapted for Ease in connection with theconnecting mem- As here shown, a-switch unit 10 is adapted to besupported movably on the track 11 in the cell 12 which has the rear wall13 and bottom wall 14. A door 15 may comprise the front wall of the celland may pivot "about the axis of the pivot pin 16 to admit the movementof the switch into and out of the celll l Fixed connecting Ymeans 17 arecarried by the rear wall 13 of the cell and have endportions extendedoutwardly beyond said rear wall for connection with circuit leads; andthe other ends, of said connecting means extend within the cell forconnection with the switch. The switch may have the stationary switchmembers 18 rising from Jthe top wall thereof; and said switch membersgood friction fit therein;

vat

are adapted to be connected with said cell connecting means. y

lln accordance with this invent-ion, terminal members 20 are secured tothe ends 'of the fixed cell connecting means disposed within the cell.Each terminal member may comprise a relatively massive block,vpreterably of copper, having an aperture in one end thereof in which theend of a cell connecting means may be secured. Said terminal memberpreferably extends upwardly above said cell connecting means and itsupper end is formed with an aperture 2l adapted removably to receiverotatably a connecting member hereinafter to bedescribed. Preferablysaid block, about said aperture 2l, is split both longitudinally andtransversely by the slots 22 and 22d to provide the spring fingers 23which are adapted to engage the connecting member frictionally.

rllhe terminal member 25 forthe stationary switch members of the switchare `similarly formed, in that said members have the apertures 26 andspring fingers 27, and the lower ends of said members are formed withthe offset ears 28 by which said members are secured to thestationaryswitch mem` bers.

The switch terminal .members are arranged on the stationary switchmembers in oppositely offset relation; that. is, the apertures 26 insaid member lie on opposite sides of the middle line of the switch andsaid apertures are in line with the corresponding apertures in theterminal member of the cell connecting means.

The means connecting said terminal members may comprise the connectingrods 30 and 3l. Said rods are preferably cylindrical and of uniformdiameter throughout the major portion of their length. although notnecessarily so formed, and are composed of some good conducting materialas copper or brass. Said rods are adapted to be extended through thealigned apertures in said cell and switch terminal members and thediameter of said rods is adapted to be substantially` Vequal orslightly. greater` than the normal diameter of the apertures in saidterminal members whereby to be a and the spring fingers 23 and 27 ofsaid terminal members are adapted to press against said rods and be ingood electrical contfact therewith and also frictional'ly retain saidrods in position. Said short rod 30 is adapted to connect the rearstationaryf.- switch member with a oell connecting means and said longrod 31 is ada ted to perform the same function with sai` frontstationary switch mem ber. It will be noted that the offset rel-ation ofthe terminalmembers for the switch members provides for ample spacingand air insulation between said c onnectingrods..

lfrom the circuit leads.

intacta Said switch terminal members preferably may be adjusted inposition about the studs ,18l of the switch members whereby to rovidefor proper alignment ot' said swltch and cell terminal members.

lV ith the arrangement above set forth, the switch may be disconnectedfrom the cell by removing said rods 3() and 31 from position in theapertures in said terminal members. The contact surfaces between saidrods and terminal members may be cleaned when' desired by rotating, orpartially rotating, Said rods in said terminal members; and saidcleaning operation may be performed while maintaining the connectionbetween said fixed connecting means and said switch members.

Said rods may be'formed with enlarged or head portions 35 which have theinternal recesses 36 and the bayonet slots 37 therein by which the rodsmay be engaged by a suitably 4formed wrench and rotated in or withdrawnfrom the terminal members. Said wrench may ,comprise the, preferably,insulating rod 40 having a handle 41 at one end and having its other endsuitably shaped to be received within the recesses 36 in said connectingrods. Said latter end of the rod is provided with the pin 42 whichextends beyond the rod on opposite sides thereof and is adapted to enterthe bayonet slots in said rods.

rlfhe door 15 of the cell may be formed with openings disposed to alignwith said connecting rods and through which the wrench may be passed toengage said connecting rods and through which said rods may be withdrawnto disconnect the switch `When it is desired to clean the contactsurfaces ot' said connecting rods, the wrench is inserted through Saidapertures 50 in the door of the cell and fitted in the head portion ofsaid rods. rlhe pin 42 carried thereby will fit in the bayonet slots insaid rods and a rotation or angular movement of said wrench will betransmitted to said rods to rotate them inthe apertures in and in frictional engagement with said terminal members and clean the contactsurfaces.

The connecting rods may be withdrawn from the terminal members by acombined rotary `and axial movement and the recesses in the head ends ofsaid rods may snugly receive the end of the wrench whereb v said rodswill remain xed on the end of' the wrench while being withdrawn throughthe openings in the door of the cell.

The invention may be contained in other` modifications without departingfrom the spirit thereof.

l claim:

1. The combination of fixed connecting means,an electric switch havingstationary switch members, and means arranged to connect said xeconnecting means en@ eweh membes elieetmeely and. admit the Meaning ethecome@ eurfeeee Whe men'enng eeetr'ee eemneeem there- 'bei-Ween.

2. The eemeeeten of e "Red eeeneeeg means, an eleese swtea hee/'mg e,stationery @W-eh e Cenneeef eemged eemmec; seid el eeemectng means se.ich membef eecmeey be mir/meme its @ennemie-ne,

3. The eeml -mien e e -ec eoexeetng means., an eeewse having emtemeySwitch membe ene; eemmeet xed comme" g means and; ewe membe @meetingmembe mem with beh sem exec eenneeng eeme endl ewseh me bem eeeeeeeeeneefg sal eme j eene et 's enel with e l feue wwe eelemect- .vfaehhaving 'fe-we sige- 'lenezy swim@ mel eem emege in lnee ene en? seidfixed cenmeeteg means, emi means te eenneet seid aed connecting meansand sweeh members Temevehj/ neuengfefmem ers efe-wier by sei@ ewehmembere each haw x" epeluie deeeim9 sei@ eme em'enge with ehe epetufeetheein espesed en opposite sides of the Switch, emlna membes carried bysaid Xe-d con neetno meen@ having eperues theein ee rangedi L with theepemures in sei@ swch e @eel members., am@ connecting fede ewengeelemeveby be received 8., eembmeten e een including a Tee- Wed e, dem, eheeebme emech eend emevebly wie?. lm the ee between eem. WeB and dem xefeenneemg means ferA engagement with n 'D W Sele. eene/esem@ lee-lea ef.een e comme@ '1g ehgueech wim GERGE BURNHAM;

